Iphoto and Catalina

No.

iPhoto was discontinued 5 years ago. It is no longer developed or sold. It was replaced by the more powerful (and free) Photos.app that comes with the OS. You can migrate to that app very simply:

Hold down the option (or alt) key and launch Photos. From the resulting menu select 'Choose Library' and point at your iPhoto Library. It will do the rest.

If you prefer not to use Photos there are several 3rd party apps that you can use. Which to choose depends on the kind of photographer you are and your budget.

Events in iPhoto are automatically converted to albums in Photos. You can find them in a folder called iPhoto Events, in the Photos window.

So there is nothing to be gained by making albums from Events before migrating.

In iPhoto, yes, deleting Events delete the actual photographs.